Automotive instrument virtual image display
US5278532A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 14, 1987 |
| Grant date | Jan 11, 1994 |
| Priority date | — |
| Expiry date | Sep 14, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2027/0165
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A compact, inexpensive and mass-producible optical display system for an automobile creates a highly visible and sharp, high contrast and pleasing, multi-color magnified virtual image of a primary instrument cluster at a viewing distance which is greater than the actual optical distance between the dashboard and the driver's eyes in order to enhance instrument readability, minimize driver eye strain, and reduce eye focus problems which are associated with transitioning between the far range viewing used for watching the road ahead and the near range viewing used for glancing at the instruments. A non-pupil forming display system uses a single off-axis aspherical mirror with power to create a virtual image of a miniaturized, multi-color passive image source, such as a segmented LCD panel, which is backlighted by a small filament incandescent light bulb. The aspheric surface is optimized to minimize aberrations and reduce vertical disparity and field curvature. The image source is pre-distorted to compensate for distortion in the off-axis configuration. A holographic diffusing screen element laminated onto the image source provides uniform high brightness and uniform contrast over th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.